1. Field of the Invention
The present invention relates to an automated method and related apparatus for rapidly and efficiently inspecting automotive wheels of different models and, more specifically, it relates to such a system wherein hardware changes to the structure of the system are not required in order to permit conversion from inspection of one model automotive wheel to another.
2. Description of the Prior Art
Numerous means have been known for inspecting automotive tires to determine the identity or certain characteristics of the tire.
U.S. Pat. No. 3,810,159 discloses the use of a camera in reading an identification pattern on a tire by detecting temperature variations with an infrared sensor.
U.S. Pat. No. 3,781,798 discloses a mechanically contacting system, which is employed to detect markings on a tire.
U.S. Pat. No. 6,124,925 discloses a device for assessing the quality of a tire through the use of a reading device that reads a marking on a tire side wall which in turn provides an indication of tire dimensions. See also U.S. Pat. No. 3,801,957.
U.S. Pat. No. 5,054,918 discloses a tire identification system that employs rotation of the tire and detection of the tire dimensions employing a fixed light source and fixed camera.
U.S. Pat. No. 3,930,141 discloses a tire inspection system having a camera, which is horizontally moveable. A separate tire dimension-measuring device is employed. This system, therefore, discloses the use of a combination of a tire measurement device and a camera to detect classification marks on a tire.
U.S. Pat. No. 6,226,081 is not related to automotive wheels. It employs a zoom lens bearing camera in a bottle inspection system.
It has been known to employ an inspection system for identifying components on an electronic circuit board through the use of a camera and an annular florescent lamp.
U.S. Pat. No. 6,151,407 discloses an inspection system employing a camera and an annular florescent lamp.
U.S. Pat. No. 4,700,078 discloses a method of inspecting tires to read on a single tire type and size tire information marks which tend to identify tire kind, tire size and other characteristics. This system employs a camera adapted for orthogonal movement as well as an annular light source. It also is reading an information providing mark.
In spite of the foregoing prior art disclosures, there remains a very real and substantial need for a method and associated apparatus for inspection of an automotive wheel to determine the position of a reference feature such that the feature is employed as a positioning means for a position indicator so that the wheel may be provided in the precise desired orientation in order to facilitate subsequent machining or other fabricating operations on the wheel.
The present invention has met the hereinbefore described needs. More specifically, the preferred method of the present invention, an automotive wheel having a reference feature is randomly placed within an inspection station, which has a light source for illuminating the wheel and a camera having a zoom lens. The wheel is illuminated and the camera obtains an initial image of the wheel from a first position and delivers first image information to a processor. The processor employs this information to make a specific determination of which model automotive wheel is being inspected and employs parameters related to that specific model in inspecting the wheel. The processor determines the position of the reference feature and if it is not in the desired position, initiates rotation of the automotive wheel to move the reference feature toward the desired position. The light source, camera and zoom lens are then moved closer to the reference feature and the camera is employed to obtain a second image with second image information being delivered to the processor. The processor employs the second image information to determine if the reference feature is in the desired position and if not, initiates rotation of the automotive wheel to move the reference feature to the desired location. When the reference feature is in the desired final position, inspection of the wheel is effected. The wheel is either accepted or rejected. The wheel, if accepted, may then be removed such as by a robot, for example, to deliver it to a first fabricating stage while preserving the desired orientation. If the wheel is rejected it is removed as by an exit conveyor to permit inspection of the next wheel.
Apparatus of the preferred embodiment of the invention provides an automotive wheel support for receiving, elevating and rotating the automotive wheel. A light source, which may be an annular florescent light source, overlies the automotive wheel support as does a camera and zoom lens. First image information provides an initial image and determines what model wheel is being inspected and employs those parameters to determine if the reference feature is in a desired position and if not, initiates rotation of the automotive wheel to the desired position. The light source, camera and zoom lens are then moved to a position closer to the reference feature, and a zoomed second image is obtained by the camera with the zoomed second image information being delivered to the processor which, in turn, makes a comparison between the desired position for the reference feature of the particular automotive wheel model and the actual position and if there is a difference, initiates rotational movement of the automotive wheel to position the referenced feature in the desired location. After that, the automotive wheel is removed from the inspection station for delivery, in an indexed manner, to the first fabricating station. A controller controls operation of the units of the system responsive to output signals received from the processor.
It is an object of the present invention to provide a method and associated apparatus for efficient, rapid and accurate inspection of an automotive wheel to make sure that a reference feature is in a proper location for the subsequent fabrication operations.
It is another object of the present invention to provide such a system, which can readily identify the model of automotive wheel being inspected, and adjust to changes in model without requiring hardware changes to the structure of the inspection station.
It is another object of the present invention to provide such a system wherein a plurality of stages of rotational movement of the automotive wheel, pursuant to control signals issued by a processor, may be employed to establish the desired reference feature position.
It is another object of the present invention to provide such a system, which can effectively accomplish the foregoing objectives, even with a conveyor delivering randomly intermixed automotive wheel models to the inspection station.
It is yet another object of the present invention to provide such a system wherein different models are adapted for through software-contained information and operations, which obviate the need for model change hardware.
It is a further object of the present invention to provide such a system, which will function effectively with a plurality of different types of reference features.
These and other objects of the present invention will be more fully understood from the following detailed description of the invention on reference to the illustrations appended hereto.